scholarly journals Complex Systems, Trade‐Offs, and Theoretical Population Biology: Richard Levin's “Strategy of Model Building in Population Biology” Revisited

2003 ◽  
Vol 70 (5) ◽  
pp. 1496-1507 ◽  
Author(s):  
Jay Odenbaugh
Keyword(s):  
Complex Systems ◽  
Population Biology ◽  
Model Building ◽  
Trade Offs ◽  
Theoretical Population ◽  
Theoretical Population Biology

The 2018 Marcus W. Feldman Prize in Theoretical Population Biology

2018 ◽  
Vol 119 ◽  
pp. 1-2 ◽  
Author(s):  
Noah A. Rosenberg
Keyword(s):  
Population Biology ◽  
Theoretical Population ◽  
Theoretical Population Biology

Preface to the Theoretical Population Biology special issue on learning

2014 ◽  
Vol 91 ◽  
pp. 1-2 ◽  
Author(s):  
Marcus W. Feldman ◽  
Kenichi Aoki
Keyword(s):  
Population Biology ◽  
Special Issue ◽  
Theoretical Population ◽  
Theoretical Population Biology

Transient analyses of population dynamics using matrix projection models

2021 ◽  
pp. 197-212
Author(s):  
David N. Koons ◽  
David T. Iles ◽  
Iain Stott
Keyword(s):  
Population Dynamics ◽  
Population Biology ◽  
Empirical Studies ◽  
Stage Structure ◽  
Transient Dynamics ◽  
Natural Environments ◽  
Matrix Projection Models ◽  
Theoretical Population ◽  
Theoretical Population Biology

The bulk of theoretical population biology has focused on long-term, asymptotic population dynamics for which tractable analytical solutions can be derived for particular questions. Following suit, the vast majority of empirical studies have focused on the established parameters provided by theory, such as the asymptotic population growth rate associated with a stable stage structure. But ‘there is nothing permanent [in natural environments] except change’ (Heraclitus), and thus there are good reasons to expect nonstable stage structures in real populations. The urgency of global change is indeed prompting increasing popularity of studying the transient dynamics caused by nonstable stage structures that occur before asymptotic dynamics are reached. This chapter provides an introduction to the concepts and analysis of transient dynamics using matrix projection models and ample examples.

scholarly journals Topics in Theoretical Population Biology

1983 ◽  
Vol 23 (4) ◽  
pp. 163-163
Author(s):  
Hirotsugu MATSUDA
Keyword(s):  
Population Biology ◽  
Theoretical Population ◽  
Theoretical Population Biology

scholarly journals Illuminating women’s hidden contribution to the foundation of theoretical population genetics

2018 ◽  
Author(s):  
Samantha Kristin Dung ◽  
Andrea López ◽  
Ezequiel Lopez Barragan ◽  
Rochelle-Jan Reyes ◽  
Ricky Thu ◽  
...  
Keyword(s):  
Population Genetics ◽  
Gender Gap ◽  
Role Models ◽  
Population Biology ◽  
Evolutionary Genetics ◽  
Numerical Work ◽  
Early Computer ◽  
Significant Difference ◽  
Theoretical Population ◽  
Theoretical Population Biology

AbstractPlentiful evidence shows an historic and continuing gender gap in participation and success in scientific research. However, less attention has been directed at clarifying obscured contributions of women to science. The lack of visible women role models (particularly in computational fields) contributes to a reduced sense of belonging and retention among women. We seek to counteract this cycle by illuminating the contribution of women programmers to the foundation of our own fields—population and evolutionary genetics. We consider past ‘acknowledged programmers’ (APs), who developed, ran, and sometimes analyzed the results of early computer programs. Due to authorship norms at the time, these programmers were credited in the acknowledgments sections of manuscripts, rather than being recognized as authors. For example, one acknowledgement reads “I thanks Mrs. M. Wu for help with the numerical work, and in particular for computing table I.”. We identified APs in Theoretical Population Biology articles published between 1970 and 1990. While only 7% of authors were women, 43% of APs were women. This significant difference (p = 4.0×10−10) demonstrates a substantial proportion of women’s contribution to foundational computational population genetics has been unrecognized. The proportion of women APs, as well as number of APs decreased over time. These observations correspond to the masculinization of computer programming, and the shifting of programming responsibilities to individuals credited as authors (likely graduate students). Finally, we note recurrent APs who contributed to several highly-cited manuscripts. We conclude that, while previously overlooked, historically, women have made substantial contributions to computational biology.

Fifty years of Theoretical Population Biology

2020 ◽  
Vol 133 ◽  
pp. 1-12
Author(s):  
Noah A. Rosenberg
Keyword(s):  
Population Biology ◽  
Theoretical Population ◽  
Theoretical Population Biology

scholarly journals Soil as an Archetype of Complexity: A Systems Approach to Improve Insights, Learning, and Management of Coupled Biogeochemical Processes and Environmental Externalities

Soil Systems ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 39
Author(s):  
Benjamin L. Turner
Keyword(s):  
Complex Systems ◽  
Systems Approach ◽  
Environmental Externalities ◽  
Supporting Evidence ◽  
Soil System ◽  
Tillage Practices ◽  
Trade Offs ◽  
Tightly Coupled ◽  
Conservation Adoption ◽  
Systems Framework

Due to tightly coupled physical, chemical, and biological processes that often behave in nonlinear, counterintuitive ways, it is argued that soil is an archetype of a complex system. Unfortunately, human intuition and decision making has been shown to be inadequate when dealing with complex systems. This poses significant challenges for managers or policy makers responding to environmental externalities where soil dynamics play a central role (e.g., biogeochemical cycles) and where full ranges of outcomes result from numerous feedback processes not easily captured by reductionist approaches. In order to improve interpretation of these soil feedbacks, a dynamic systems framework is outlined (capturing feedback often excluded from investigation or left to intuition) and then applied to agroecosystem management problems related to irrigation or tillage practices that drive nutrient cycling (e.g., soil water, nitrogen, carbon, and sodium). Key soil feedbacks are captured via a variety of previously developed models simulating soil processes and their interactions. Results indicated that soil system trade-offs arising from conservation adoption (drip irrigation or no-tillage) provided reasonable supporting evidence (via compensating feedbacks) to managers justifying slow adoption of conservation practices. Modeling soils on the foundation provided in the complex systems sciences remains an area for innovations useful for improving soil system management.

Practical approaches for subsalt velocity model building

Geophysics ◽  
2008 ◽  
Vol 73 (5) ◽  
pp. VE183-VE194 ◽  
Author(s):  
Junru Jiao ◽  
David R. Lowrey ◽  
John F. Willis ◽  
Ruben D. Martínez
Keyword(s):  
Software Package ◽  
Model Building ◽  
Velocity Model ◽  
Fine Tuning ◽  
Inherent Difficulty ◽  
Velocity Models ◽  
First Approximation ◽  
Velocity Model Building ◽  
Trade Offs ◽  
Efficient Performance

Imaging sediments below salt bodies is challenging because of the inherent difficulty of estimating accurate velocity models. These models can be estimated in a variety of ways with varying degrees of expense and effectiveness. Two methods are commercially viable trade-offs. In the first method, residual-moveout analysis is performed in a layer-stripping mode. The models produced with this method can be used as a first approximation of the subsalt velocity field. A wave-equation migration scanning technique is more suitable for fine-tuning the velocity model below the salt. Both methods can be run as part of a sophisticated interactive velocity interpretation software package that makes velocity interpretation efficient. Performance of these methods has been tested on synthetic and field data examples.

scholarly journals Probabilistic moveout analysis by time warping

Geophysics ◽  
2020 ◽  
Vol 85 (1) ◽  
pp. U1-U20
Author(s):  
Yanadet Sripanich ◽  
Sergey Fomel ◽  
Jeannot Trampert ◽  
William Burnett ◽  
Thomas Hess
Keyword(s):  
Parameter Estimation ◽  
Posterior Probability ◽  
Model Building ◽  
Probability Distributions ◽  
Real Data ◽  
Inversion Method ◽  
Time Warping ◽  
Anisotropic Models ◽  
Trade Offs ◽  
Set Up

Parameter estimation from reflection moveout analysis represents one of the most fundamental problems in subsurface model building. We have developed an efficient moveout inversion method based on the process of automatic flattening of common-midpoint (CMP) gathers using local slopes. We find that as a by-product of this flattening process, we can also estimate reflection traveltimes corresponding to the flattened CMP gathers. This traveltime information allows us to construct a highly overdetermined system and subsequently invert for moveout parameters including normal-moveout velocities and quartic coefficients related to anisotropy. We use the 3D generalized moveout approximation (GMA), which can accurately capture the effects of complex anisotropy on reflection traveltimes as the basis for our moveout inversion. Due to the cheap forward traveltime computations by GMA, we use a Monte Carlo inversion scheme for improved handling of the nonlinearity between the reflection traveltimes and moveout parameters. This choice also allows us to set up a probabilistic inversion workflow within a Bayesian framework, in which we can obtain the posterior probability distributions that contain valuable statistical information on estimated parameters such as uncertainty and correlations. We use synthetic and real data examples including the data from the SEAM Phase II unconventional reservoir model to demonstrate the performance of our method and discuss insights into the problem of moveout inversion gained from analyzing the posterior probability distributions. Our results suggest that the solutions to the problem of traveltime-only moveout inversion from 2D CMP gathers are relatively well constrained by the data. However, parameter estimation from 3D CMP gathers associated with more moveout parameters and complex anisotropic models are generally nonunique, and there are trade-offs among inverted parameters, especially the quartic coefficients.

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